It is in Edron, about 51 steps south of the spot the map marks with that name.

And 5 down from the surface once you are there.

• 1 — Edron, as the map itself names it
• 2 — the ground above the treasure

• A rope. You drop in through a hole, and a rope is how you climb back out.
• Something for giant spider, orc leader and orc berserker — they live down there.

The chest is 5 floors under the surface. Going down over it, this is what each floor uses:

1. Ground: down through stairs.
2. 1 down: down through a ladder.
3. 3 down: down through a hole.
4. 4 down: down through a hole.

• 1 — the way in: stairs, ground
• → — the treasure lies this way

• 2 — a ladder, 1 down
• → — the treasure lies this way

• 3 — a hole, 3 down
• → — the treasure lies this way

• 4 — a hole, 4 down
• → — the treasure lies this way

Some floors are not on the list: their way down is further off than the rest, and that stretch you have to find yourself.

• 1 — the chest

One chest, one reward.